Intra-cardiac echocardiography inteposer

ABSTRACT

An imaging catheter assembly is provided. The imaging catheter assembly includes an interposer including a multi-layered substrate structure, wherein the multi-layered substrate structure includes a first plurality of conductive contact pads coupled to a second plurality of conductive contact pads via a plurality of conductive lines; an imaging component coupled to the interposer via the first plurality of conductive contact pads; and an electrical cable coupled to the interposer via the second plurality of conductive contact pads and in communication with the imaging component.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/338,820, filed Apr. 2, 2019, now U.S. Pat. No. 11,426,140, which isthe U.S. National Phase application under 35 U.S.C. § 371 ofInternational Application No. PCT/EP2017/075092, filed on Oct. 3, 2017,which claims the benefit of and priority to U.S. Provisional ApplicationNos. 62/403,278, filed Oct. 3, 2016, and 62/434,489, filed Dec. 15,2016, which are incorporated by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates generally to imaging catheters, inparticular, to imaging assemblies and the interconnection between animaging assembly and a cable of an imaging system.

BACKGROUND

Diagnostic and therapeutic ultrasound catheters have been designed foruse inside many areas of the human body. In the cardiovascular system,two common diagnostic ultrasound methods are intravascular ultrasound(IVUS) and intra-cardiac echocardiography (ICE). Typically a singlerotating transducer or an array of transducer elements is used totransmit ultrasound at the tips of the catheters. The same transducers(or separate transducers) are used to receive echoes from the tissue. Asignal generated from the echoes is transferred to a console whichallows for the processing, storing, display, or manipulation of theultrasound-related data.

IVUS catheters are typically used in the large and small blood vessels(arteries or veins) of the body, and are almost always delivered over aguidewire having a flexible tip. ICE catheters are usually used to imagechambers of the heart and surrounding structures, for example, to guideand facilitate medical procedures, such as transseptal lumen punctures,left atrial appendage closures, atrial fibrillation ablation, and valverepairs. Commercially-available ICE catheters are not designed to bedelivered over a guidewire, but instead have distal ends which can bearticulated by a steering mechanism located in a handle at the proximalend of the catheter. For example, an ICE catheter may be insertedthrough the femoral or jugular vein when accessing the anatomy, andsteered in the heart to acquire images necessary to the safety of themedical procedures.

An ICE catheter typically includes an ultrasound imaging component thatgenerates and receives acoustic energy. The imaging component mayinclude an array of transducer elements or transducer elements arrangedin any suitable configuration. The imaging component is encased in a tipassembly located at a furthest distal tip of the catheter. The tipassembly is covered with acoustic adhesive materials. An electricalcable is connected to the imaging component and extends through the coreof the body of the catheter. The electrical cable may carry controlsignals and echo signals to facilitate imaging of the heart anatomy. Thedevice may provide rotational, 2-way, or 4-way steering mechanisms suchthat anterior, posterior, left, and/or right views of the heart anatomymay be imaged.

One approach to interconnecting an electrical cable to an imagingcomponent of an imaging catheter is to directly connect or solder theelectrical cable to the imaging component. However, the directinterconnection may create tension on the imaging component while thecatheter is maneuvered to a desired location, and thus may not bedesirable. Another approach is to employ a separate flex circuit orprinted circuit board (PCB) to interconnect the electrical cable and theimaging component. For example, components, such as capacitors andthermistors, may be mounted on the PCB to provide the interconnection.The PCB may include traces or signal lines and vias. The traces may havewidths of about 20 micrometers (μm) to about 50 μm and may be spacedapart by about 20 μm to about 50 μm. The vias may have sizes in therange of hundreds of μm. Thus, although the use of a separate flexcircuit or PCB may reduce tension on the imaging component, the flexcircuit or the PCB may not be suitable for use in an imaging catheterdue to the limited space available within the imaging catheter.

SUMMARY

The invention provides devices, systems, and related methods forinterconnecting imaging assemblies with electrical cables of imagingsystems that overcome the limitations associated with previous designs.

Embodiments of the present disclosure provide an interposer devicesuitable for interconnecting an imaging component and an electricalcable. The interposer device is formed from a multi-layered substratestructure including at least one intermediate conductive metal layerpositioned between a top metal layer and a base substrate layer. The topmetal layer is plated with electroless nickel palladium immersion gold(ENEPIG) to from conductive contact pads. The ENEPIG material issuitable for both soldering and wirebonding. The intermediate conductivemetal layer is patterned with conductive traces to form signal pathsbetween the conductive contact pads. In an embodiment, the imagingcomponent is wire-bonded to the interposer via a first subset of theconductive contact pads. The electrical cable is soldered to theinterposer via a second subset of the conductive contact pads.Additional surface-mount components can be mounted on a third subset ofthe conductive contact pads to provide additional functionalities suchas power regulation. The interposer device provide dense and precisesignal traces for signal distribution and routing without including anylogic as in typical semiconductor devices. The dense and preciseplacement of the signal traces allows the interposer device to have aform factor suitable for use in catheter assembly.

In one embodiment, an imaging catheter assembly is provided. The imagingcatheter includes an interposer including a multi-layered substratestructure, wherein the multi-layered substrate structure includes afirst plurality of conductive contact pads coupled to a second pluralityof conductive contact pads via a plurality of conductive lines; animaging component coupled to the interposer via the first plurality ofconductive contact pads; and an electrical cable coupled to theinterposer via the second plurality of conductive contact pads and incommunication with the imaging component.

In some embodiments, the interposer includes: a top conductive layerincluding the first plurality of conductive contact pads and the secondplurality of conductive contact pads; a base substrate material layer;and at least one intermediate conductive layer positioned between thetop conductive layer and the base substrate material layer, wherein theplurality of conductive lines extend through the at least oneintermediate conductive layer. In some embodiments, the base substratematerial layer includes at least one of ceramic, glass, quartz, alumina,sapphire, or silicon. In some embodiments, the top conductive layerfurther includes: a third plurality of conductive contact pads coupledto the plurality of conductive lines; and a surface-mount componentmounted on the third plurality of conductive contact pads. In someembodiments, the surface-mount component is a power-regulatingcomponent. In some embodiments, the interposer has a width less than 4millimeter (mm). In some embodiments, the interposer has a length lessthan 15 millimeter (mm). In some embodiments, the imaging component iswire-bonded to the interposer via the first plurality of conductivecontact pads. In some embodiments, the electrical cable is soldered tothe interposer via the second plurality of conductive contact pads. Insome embodiments, the imaging component includes an integrated circuit(IC) layer positioned between an acoustic layer and a backing layer. Insome embodiments, the imaging component is a planar component, andwherein the interposer is positioned coplanar or parallel to a plane ofthe imaging component. In some embodiments, the backing layer is longerthan the IC layer such that a portion of the backing layer extendsbeyond the IC layer, and wherein the interposer is positioned on theportion of the backing layer that extends beyond the IC layer. In someembodiments, the plurality of conductive lines includes at least one ofa power line, a control line, or a signal line. In some embodiments, theimaging catheter assembly further comprises a flexible elongate memberincluding a distal portion and a proximal portion, wherein the imagingcomponent and the interposer are coupled to the distal portion of theflexible elongate member.

In one embodiment, a method of manufacturing an imaging catheterassembly is provided. The method includes forming an interposercomprising a multi-layered substrate structure including a firstplurality of conductive contact pads coupled to a second plurality ofconductive contact pads via a plurality of conductive lines; coupling animaging component to the first plurality of conductive contact pads ofthe interposer; and coupling an electrical cable to the second pluralityof conductive contact pads of the interposer.

In some embodiments, the forming the interposer includes: forming a basesubstrate material layer; forming a top conductive layer including thefirst plurality of conductive contact pads and the second plurality ofconductive contact pads; and forming one or more intermediate conductivelayers positioned between the top conductive layer and the basesubstrate material layer, wherein the plurality of conductive linesextend through the one or more intermediate conductive layers. In someembodiments, the method further comprises coupling a surface-mountcomponent to interposer. In some embodiments, the coupling theelectrical cable to the second plurality of conductive contact padsincludes soldering. In some embodiments, the coupling the imagingcomponent to the first plurality of conductive contact pads includeswirebonding. In some embodiments, the method further comprises mountingthe interposer to a backing layer of the imaging component.

Additional aspects, features, and advantages of the present disclosurewill become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present disclosure will be describedwith reference to the accompanying drawings, of which:

FIG. 1 is a schematic diagram of an intraluminal imaging systemaccording to embodiments of the present disclosure.

FIG. 2 is a schematic diagram of a portion of an intraluminal deviceaccording to embodiments of the present disclosure.

FIG. 3 is a schematic diagram of a tip assembly according to embodimentsof the present disclosure.

FIG. 4A is a perspective view of an imaging component according toembodiments of the present disclosure.

FIG. 4B is a cross-sectional view of an imaging component according toembodiments of the present disclosure.

FIG. 5 is a flow diagram of a method of manufacturing a tip assemblyaccording to embodiments of the present disclosure.

FIG. 6 is a cross-sectional view of an interposer according toembodiments of the present disclosure.

FIG. 7 is a top view of an intermediate conductive layer of aninterposer according to embodiments of the present disclosure.

FIG. 8 is a cross-sectional view of an interposer with a bond wire andan electrical cable coupled in position according to embodiments of thepresent disclosure.

FIG. 9 is a perspective view of an interposer with an electrical cableand surface-mount components coupled in position according toembodiments of the present disclosure.

FIG. 10 is a perspective of an interposer and an imaging componentpositioned for coupling according to embodiments of the presentdisclosure.

FIG. 11 is a cross-sectional view of an interposer and an imagingcomponent coupled in position according to embodiments of the presentdisclosure.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It is nevertheless understood that no limitation tothe scope of the disclosure is intended. Any alterations and furthermodifications to the described devices, systems, and methods, and anyfurther application of the principles of the present disclosure arefully contemplated and included within the present disclosure as wouldnormally occur to one skilled in the art to which the disclosurerelates. For example, while the intraluminal system is described interms of cardiovascular imaging, it is understood that it is notintended to be limited to this application. The system is equally wellsuited to any application requiring imaging within a confined cavity. Inparticular, it is fully contemplated that the features, components,and/or steps described with respect to one embodiment may be combinedwith the features, components, and/or steps described with respect toother embodiments of the present disclosure. For the sake of brevity,however, the numerous iterations of these combinations will not bedescribed separately.

FIG. 1 is a schematic diagram of an intraluminal imaging system 100according to embodiments of the present disclosure. The system 100 mayinclude an intraluminal device 110, a connector 124, a control andprocessing system 130, such as a console and/or a computer, and amonitor 132. The intraluminal device 110 includes a tip assembly 102, aflexible elongate member 108, and a handle 120. The flexible elongatemember 108 includes a distal portion 104 and a proximal portion 106. Thedistal end of the distal portion 104 is attached to the tip assembly102. The proximal end of the proximal portion 106 is attached to thehandle 120 for example, by a resilient strain reliever 112, formanipulation of the intraluminal device 110 and manual control of theintraluminal device 110. The tip assembly 102 can include an imagingcomponent with ultrasound transducer elements and associated circuitry.The handle 120 can include actuators 116, a clutch 114, and othersteering control components for steering the intraluminal device 110. Inan embodiment, the intraluminal device 110 is an ICE device.

The handle 120 is connected to the connector 124 via another strainreliever 118 and an electrical cable 122. The connector 124 may beconfigured in any suitable configurations to interconnect with theprocessing system 130 and the monitor 132 for processing, storing,analyzing, manipulating, and displaying data obtained from signalsgenerated by the imaging component at the tip assembly 102. Theprocessing system 130 can include one or more processors, memory, one ormore input devices, such as keyboards and any suitable command controlinterface device. The processing system 130 can be operable tofacilitate the features of the intraluminal imaging system 100 describedherein. For example, the processor can execute computer readableinstructions stored on the non-transitory tangible computer readablemedium. The monitor 132 can be any suitable display device, such asliquid-crystal display (LCD) panel or the like.

In operation, a physician or a clinician advances the flexible elongatemember 108 into a vessel within a heart anatomy. The physician orclinician can steer the flexible elongate member 108 to a position nearthe area of interest to be imaged by controlling the actuators 116 andthe clutch 114 on the handle 120. For example, one actuator 116 maydeflect the tip assembly 102 and the distal portion 104 in a left-rightplane and the other actuator 116 may deflect the tip assembly 102 andthe distal portion 104 in an anterior-posterior plane. The clutch 114provides a locking mechanism to lock the positions of the actuators 116and in turn the deflection of the flexible elongate member 108 whileimaging the area of interest.

The imaging process may include activating the ultrasound transducerelements on the tip assembly 102 to produce ultrasonic energy. A portionof the ultrasonic energy is reflected by the area of interest and thesurrounding anatomy, and the ultrasound echo signals are received by theultrasound transducer elements. The connector 124 transfers the receivedecho signals to the processing system 130 where the ultrasound image isreconstructed and displayed on the monitor 132. In some embodiments, theprocessing system 130 can control the activation of the ultrasoundtransducer elements and the reception of the echo signals. In someembodiments, the processing system 130 and the monitor 132 may be partof the same system.

The system 100 may be utilized in a variety of applications such astransseptal punctures, left atrial appendage closures, atrialfibrillation ablation, and valve repairs and can be used to imagevessels and structures within a living body. In addition, the tipassembly 102 may include any suitable physiological sensor or componentfor diagnostic, treatment, and/or therapy. For example, the tip assemblycan include an imaging component, an ablation component, a cuttingcomponent, a morcellation component, a pressure-sensing component, aflow-sensing component, a temperature-sensing component, and/orcombinations thereof.

FIG. 2 is a schematic diagram of a portion of the intraluminal device110 according to embodiments of the present disclosure. The tip assembly102 and the flexible elongate member 108 are shaped and sized forinsertion into vessels of a patient body. The flexible elongate member108 can be composed of any suitable material, such as Pebax® polyetherblock amides. The distal portion 104 and the proximal portion 106 aretubular in shape and may include one or more lumens extending along alength of the flexible elongate member 108. In some embodiments, onelumen (e.g., a primary lumen) may be sized and shaped to accommodate anelectrical cable 340 (shown in FIG. 3 ) interconnecting the tip assembly102 and the connector 124 for transferring echo signals obtained fromthe transducer elements. In addition, the lumen may be shaped and sizedto accommodate other components for diagnostic and/or therapyprocedures. In some other embodiments, one or more lumens (e.g.,secondary lumens) may be sized and shaped to accommodate steering wires,for example, extending from the distal portion 104 to the handle 120.The steering wires may be coupled to the actuators 116 and the clutch114 such that the flexible elongate member 108 and the tip assembly 102are deflectable based on actuations of the actuators 116 and the clutch114. Dimensions of the flexible elongate member 108 can vary indifferent embodiments. In some embodiments, the flexible elongate member108 can be a catheter having an outer diameter between about 8 and about12 French (Fr) and can have a total length 206 between about 80centimeters (cm) to about 120 cm, where the proximal portion 106 canhave a length 204 between about 70 cm to about 118 cm and the distalportion 104 can have a length 202 between about 2 cm to about 10 cm.

FIG. 3 is a schematic diagram of the tip assembly 102 according toembodiments of the present disclosure. FIG. 3 provides a more detailedview of the tip assembly 102. The tip assembly 102 includes a tip member310, an imaging component 320, and an interposer 330. The tip member 310has a tubular body sized and shaped for insertion into a patient body.The tip member 310 can be composed of a thermoplastic elastomer materialor any suitable biocompatible material that has acoustic impedancematching to blood within a vessel of a patient body when in use. Forexample, the tip member 310 can be composed of Pebax® polyether blockamides. Dimensions of the tip member 310 can vary in differentembodiments and may depend on the size of the catheter or the flexibleelongate member 108. In some embodiments, the tip member 310 can includea length 302 between about 15 millimeter (mm) to about 30 mm and a width304 between about 2 mm to about 4 mm.

The interposer 330 interconnects the imaging component 320 to anelectrical cable 340. The imaging component 320 emits ultrasound energyand receives ultrasound echo signals reflected by surrounding tissuesand vasculatures. The imaging component 320 is described in greaterdetail herein with references to FIG. 4 . The electrical cable 340carries the ultrasound echo signals to the processing system 130 forimage generation and analysis. In addition, the electrical cable 340 cancarry control signals for controlling the imaging component 320.Further, the electrical cable 340 can carry power for powering theimaging component 320. The electrical cable 340 extends along a lengthof the flexible elongate member 108. The interposer 330 functions as aninterconnect to distribute or transfer signals between the imagingcomponent 320 and the electrical cable 340. The interposer 330 can becomposed of any suitable substrate material, such as ceramic, glass,quartz, alumina, sapphire, and silicon, that may provide high-densitysignal routing in a small form factor. In some embodiments, theinterposer 330 may leverage semiconductor processes, but may not includeactive components such as transistors as in typical semiconductordevices. The interposer 330 is described in greater detail herein withreferences to FIGS. 5-10 .

FIG. 4A is a perspective view of the imaging component 320 according toembodiments of the present disclosure. FIG. 4B is a cross-sectional viewof the imaging component 320 take along the line 401 of FIG. 4Aaccording to embodiments of the present disclosure. The imagingcomponent 320 is a planar component including an acoustic layer 322, anintegrated circuit (IC) layer 326, and a backing layer 328. The IC layer326 is positioned between the acoustic layer 322 and the backing layer328. In some other embodiments, the backing layer 328 may be between theacoustic layer 322 and the IC layer 326 with electrical connections madethrough the backing layer 328.

The acoustic layer 322 includes an array of ultrasound transducerelements 324. The ultrasound transducer elements 324 are composed ofpiezoelectric material and acoustic matching layers. In alternativeembodiments, the ultrasound transducer elements 324 may be capacitivemicromachined ultrasound transducers (cMUTs). Exemplary transducers forICE have a typical thickness of approximately 0.28 mm in thepiezoelectric material to enable an 8 megahertz (MHz) ultrasound signalto be generated and transmitted at a typical velocity of 1500 meter persecond (m/sec) through blood. The ultrasound signal may propagate in thedirection as shown by the dashed arrows. The transducer thickness can beof various thicknesses ranging approximately from 0.56 mm to 0.19 mm togenerate sufficient penetration depth in tissue imaging. In general, thethickness of the transducers can be adjusted for the frequency of soundin the transmission medium for the desired penetration depth in anytissue imaging. Image intensity can be adjusted by the driving voltageon the transducers. In some embodiments, the acoustic layer 322 mayinclude a linear array of about 32 to about 128 ultrasound transducerelements 324 for two-dimensional (2D) imaging. In some otherembodiments, the acoustic layer 322 may include a matrix of about 200 toabout 2000 ultrasound transducer elements 324 for three-dimensional (3D)imaging.

The IC layer 326 includes logics and/or circuits configured to multiplexcontrol signals, for example, generated by the processing system 130,and transfer the control signals to corresponding ultrasound transducerelements 324. The controls signals can control the emission ofultrasound pulses and/or the reception of echo signals. In the reversedirection, the logics and/or circuits are configured to receiveultrasound echo signals reflected by target tissue and received by theultrasound transducer elements 324. The logics and/or circuits convertthe ultrasound echo signals into electrical signals and transfer theelectrical signals through the interposer 330 and the electrical cable340 to the processing system 130 for processing and/or display. Thelogics and/or circuits can be further configured to perform signalconditioning before transferring the signals. Signal conditioning mayinclude filtering, amplification, and beamforming. In some embodiments,beamforming can be performed to reduce the number of signal channels.For example, the number of signal channels may be between about 4 toabout 128, with some particular embodiments, of about 8. In someembodiments, the IC layer 326 may have a longer length than the acousticlayer 322. The portion 325 of the IC layer 326 extending beyond acousticlayer 322 may include a plating layer 327 for wirebonding to theinterposer 330, as described in greater detail herein. The plating layer327 may be composed of any suitable material such as gold, aluminum, andcopper, silver, and ENEPIG.

The backing layer 328 is composed of an acoustically absorptive materialso that the backing layer 328 can absorb or deaden the ultrasonic wavescoming from the back of the acoustic layer 322. For example, the backinglayer 328 may be composed of an epoxy material. In some embodiments, thebacking layer 328 may have a longer length than IC layer 326. Theportion 329 of the backing layer 328 extending beyond the IC layer 326may function as an alignment agent for aligning the interposer 330 tothe imaging component 320, as described in greater detail herein.

Dimensions of the imaging component 320 may vary in differentembodiments and may be limited by the space available in the tip member310. For example, the acoustic layer 322, the IC layer 326, and thebacking layer 328 may have about the same width 408, which may be in therange of about 1 mm to about 4 mm. The acoustic layer 322 may have alength 402 of about 5 mm to about 15 mm. The IC layer 326 may have alength 404 of about 5 mm to about 20 mm. The backing layer 328 may havea length 406 of about 5 mm to about 30 mm.

A method 500 of manufacturing the tip assembly 102 is described withreference made to FIGS. 5-9 . FIG. 5 is a flow diagram of a method 500of manufacturing the tip assembly 102 according to embodiments of thepresent disclosure. It is understood that additional steps can beprovided before, during, and after the steps of method 500, and some ofthe steps described can be replaced or eliminated for other embodimentsof the method. The steps of the method 500 can be carried out by amanufacturer of a catheter in the order as shown or any suitable order.FIG. 6 is a cross-sectional view of the interposer 330 taken along theline 309 of FIG. 3 according to embodiments of the present disclosure.FIG. 7 is a top view of an intermediate conductive layer 620 of theinterposer 330 according to embodiments of the present disclosure. FIG.8 is a cross-sectional view of the interposer 330 taken along the line309 of FIG. 3 with a bond wire 810 and the electrical cable 340 coupledin position according to embodiments of the present disclosure. FIG. 9is a perspective view of the interposer 330 with the electrical cable340 and surface-mount components 820 coupled in position according toembodiments of the present disclosure. FIG. 10 is a perspective of theinterposer 330 and the imaging component 320 positioned for couplingaccording to embodiments of the present disclosure.

Referring to the step 510 of the method 500 and FIGS. 6 and 7 , in anembodiment, an interposer comprising a multi-layered substrate structure600 is formed. The multi-layered substrate structure 600 includes afirst plurality of conductive contact pads 612 a, a second plurality ofconductive contact pads 612 b, and a third plurality of conductivecontact pads 612 c coupled by a plurality of conductive lines 622. FIG.6 illustrates the multi-layered substrate structure 600. Themulti-layered substrate structure 600 includes a top conductive layer610, one or more intermediate conductive layers 620, and a base layer630. The intermediate conductive layers 620 are positioned between thetop conductive layer 610 and the base layer 630. The base layer 630 canbe compose of any suitable substrate material, such as such as ceramic,glass, quartz, alumina, sapphire, and silicon, which may doped orun-doped. In some embodiments, standard semiconductor fabricationprocesses may be used to form the multi-layered substrate structure 600.When using un-doped silicon for the base layer 630, an additionalinsulating layer (e.g., SiO2 (silica)) may be disposed between thesilicon base layer 630 and the conductive layers 620.

The top conductive layer 610 and the intermediate conductive layers 620are composed of conductive materials such as aluminum or copper. The topconductive layer 610 is plated to form the conductive contact pads 612for connecting to the imaging component 320, the electrical cable 340,and/or other components for power regulation. In an embodiment, theconductive contact pads 612 can be composed of or plated withelectroless nickel palladium immersion gold (ENEPIG) materials, whichare materials are suitable for both soldering and wirebonding.

The intermediate conductive layers 620 are patterned to form theconductive lines 622, for example, using masking and photolithographyprocesses that are commonly used for semiconductor fabrication. Theconductive lines 622 form signal paths between the conductive contactpads 612. FIG. 7 illustrates a top view of an exemplary intermediateconductive layer 620. As shown, the conductive lines 622 are patternedon the intermediate conductive layer 620. Although the conductive lines622 are shown as straight lines, the conductive lines 622 may bepatterned in any suitable configuration. The dashed boxes show areaswhich may be coupled to the conductive contact pads 612 when stackedwith the top conductive layer 610. Dimensions of the conductive lines622 may vary in different embodiments and may be dependent thefabrication process. In some embodiments, the conductive lines 622 canhave widths 702 between about 1 μm to about 50 μm and may be spacedapart by a spacing 704 of about 1 μm to about 50 μm.

The conductive lines 622 may extend through one or more of intermediateconductive layers 620. The number of intermediate conductive layers 620may vary depending on the number of conductive lines 622 and therequired resistances for the conductive lines 622. In some embodiments,the multi-layered substrate structure 600 can have about 5 intermediateconductive layers. In addition, the multi-layered substrate structure600 may include dielectric layers between adjacent layers to provideinsulation and/or protection to the conductive lines 622.

Dimensions of the multi-layered substrate structure 600 may vary indifferent embodiments and may be limited by the size of the tip member310. In some embodiments, the multi-layered substrate structure 600includes a length 602 of less than about 15 mm, a thickness 604 of lessthan about 0.5 mm, and a width 606 (shown in FIG. 9 ) of less than 4 mm.

Referring to the step 520 of the method 500 and FIGS. 8-10 , in anembodiment, the imaging component 320 is coupled to the first pluralityof conductive contact pads 612 a of the interposer 330, for example,using wirebonding technology such as thermal compression wirebonding. Asdescribed above, the IC layer 326 of the imaging component 320 maygenerate a number of signal channels for transferring ultrasound echosignals to the electrical cable 340 for image generation. In anembodiment, the multi-layered substrate structure 600 connects eachsignal channel output by the IC layer 326 of the imaging component 320via a bond wire 810. The bond wire 810 may be composed of any suitablematerials such as gold, aluminum, or copper. As shown in FIGS. 7-10 ,one end of each bond wire 810 is bonded to one of the first plurality ofconductive contact pads 612 a. The opposite end of each bond wire 810 isbonded to the plating layer 327 of the IC layer 326. For example, theplating layer 327 may include a plurality of contact pads coupled to thesignal channel outputs.

Referring to the step 530 of the method 500 and FIGS. 8-10 , in anembodiment, the electrical cable 340 is coupled to the second pluralityof conductive contact pads 612 c of the interposer 330, for example,using soldering. As described above, the electrical cable 340 carriesthe signal channel outputs (e.g., the beamformed or multiplexedultrasound echo signals) of the IC layer 326 to the processing system130. As shown in FIGS. 8 and 9 , the electrical cable 340 includes aplurality of conductors or conductive elements 342. For example, eachsignal channel output is carried by one conductive element 342. Inaddition, one or more of the conductive elements 342 can carry controlsignals for controlling the ultrasound transducer elements 324. Forexample, the control signals may be generated by the processing system130 or other interface modules positioned between the processing system130 and the intraluminal device 110. Further, one or more of theconductive elements 342 can carry power for powering the imagingcomponent 320. The conductive elements 342 can be soldered to the firstplurality of conductive contact pads 612 c using any suitable solderingmaterial (e.g., tin, lead, and/or zinc) as shown by the soldering joint613. As shown in FIG. 10 , the electrical cable 340 is coupled to aprotector 344 protecting the portions of the conductive elements 342that are positioned on the surface of the interposer 330.

Referring to the step 540 of the method 500 and FIGS. 8-10 , in anembodiment, a surface-mount component 820 is mounted on the thirdplurality of conductive pads 612 c. For example, one or more of thesurface-mount component 820 can be mounted onto surfaces of one or moreof the third plurality of conductive pads 612 c via soldering orconductive epoxy as shown in FIGS. 8-10 . Some examples of thesurface-mount components 820 may include capacitors and thermistors,resistors, diodes, transistors, inductors. Thus, the interposer 330 mayinclude various surface-mount components to provide additionalfunctionalities such as power regulation. It should be noted that thestep 540 may be optional in some embodiments.

FIG. 11 is a cross-sectional view of the interposer 330 and the imagingcomponent 320 coupled in position according to embodiments of thepresent disclosure. The cross-sectional view is taken along the line1002 of FIG. 10 . The ultrasound transducer elements 324 in the acousticlayer 322 emit ultrasound signals (shown as solid arrows) and receiveultrasound echo signals (shown as dashed arrows) reflected bysurrounding vasculatures when in use. The logics and/or circuits of theIC layer 326 convert and process the ultrasound echo signals intoelectrical signals and transfer the electrical signals to the electricalcable 340 via the bond wires 810, the conductive contact pads 612, andthe conductive lines 622 of the interposer 330.

The interposer 330 provides several benefits. The interposer 330 canfacilitate stable interconnect between the imaging component 320 and theelectrical cable 340. The interposer 330 can form the conductive lines622 with high density and high precision. As described above, theconductive lines 622 can have widths between about 1 μm to about 50 μmand spaced apart by about 1 μm to about 50 μm, whereas typical PCBsand/or flex circuits have traces with widths between about 25 μm toabout 100 μm and spaced apart by about 25 μm to about 100 μm. Thus, thedisclosed embodiments can reduce the form factor of the interposer 330by at least an order of about 10 when compared to PCBs and/or flexcircuits. As such, the interposer 330 is suitable for use in a catheterassembly. In addition, the inclusion of the EPENIG conductive contactpads 612 in the top conductive layer 610 allows the interposer 330 to besoldered to the electrical cable 340 and wire-bonded to the imagingcomponent 320. The interposer 330 can include additional functionalitiesby including surface-mount components soldered to the EPENIG conductivecontact pads 612. Further, the interposer 330 can be fabricated inbatches. In an embodiment, hundreds of the multi-layered substratestructures 600 can be formed on a wafer with a precise singulation, forexample, about 8 μm of clearance from the outer-most conductive lines622 to the edges or cut lines of the interposer 330 part.

Persons skilled in the art will recognize that the apparatus, systems,and methods described above can be modified in various ways.Accordingly, persons of ordinary skill in the art will appreciate thatthe embodiments encompassed by the present disclosure are not limited tothe particular exemplary embodiments described above. In that regard,although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure. It is understood that such variations may be madeto the foregoing without departing from the scope of the presentdisclosure. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the presentdisclosure.

What is claimed is:
 1. An apparatus, comprising: an intraluminal imagingdevice comprising: an imaging component; and an interposer configured totransmit an electrical signal associated with the imaging component,wherein the interposer comprises a multi-layered substrate structure,wherein the imaging component is not formed on the multi-layeredsubstrate structure, and wherein the multi-layered substrate structurecomprises: a top layer comprising a first contact pad and a secondcontact pad; a base layer; and an intermediate layer disposed betweenthe top layer and the base layer, wherein the intermediate layercomprises a conductive line coupled to the first contact pad and thesecond contact pad such that the electrical signal is transmitted viathe first contact pad, the conductive line, and the second contact pad.2. The apparatus of claim 1, wherein the intraluminal imaging devicecomprises: a first conductor coupled to the imaging component and thefirst contact pad; and an electrical cable comprising a second conductorcoupled to the second contact pad.
 3. The apparatus of claim 2, whereinthe first contact pad and the second contact pad comprise a samematerial, wherein the first conductor comprises a wirebonding betweenthe imaging component and the first contact pad, and wherein the secondconductor is soldered to the second contact pad.
 4. The apparatus ofclaim 2, wherein the intraluminal imaging device comprises a pluralityof first conductors coupled to the imaging component, wherein theelectrical cable comprises a plurality of second conductors, wherein thetop layer comprises a plurality of first contact pads coupled to theplurality of first conductors and a plurality of second contact padscoupled to the plurality of second conductors.
 5. The apparatus of claim1, wherein the top layer defines a top surface of the interposer, andwherein the first contact pad and the second contact pad are exposed atthe top surface.
 6. The apparatus of claim 1, wherein the top layercomprises a third contact pad coupled to the conductive line, andwherein the interposer comprises a surface mount component coupled tothe third contact pad.
 7. The apparatus of claim 6, wherein theinterposer comprises a proximal end and a distal end, wherein the firstcontact pad is disposed at the distal end and the second contact pad isdisposed at the proximal end, and wherein the third contact pad isdisposed between the first contact pad and the second contact pad. 8.The apparatus of claim 1, wherein the conductive line extendslongitudinally within the intermediate layer.
 9. The apparatus of claim8, wherein the conductive line extends vertically within the top layerand the intermediate layer.
 10. The apparatus of claim 1, wherein themulti-layered substrate structure comprises a plurality of intermediatelayers comprising a plurality of conductive lines.
 11. The apparatus ofclaim 10, wherein the multi-layered substrate structure comprises adielectric layer disposed between adjacent layers of the plurality ofintermediate layers.
 12. The apparatus of claim 1, wherein a material ofthe base layer is different than a material of the top layer and amaterial of the intermediate layer.
 13. The apparatus of claim 1,wherein the multi-layered substrate structure comprises an insulatinglayer disposed between the base layer and the intermediate layer. 14.The apparatus of claim 1, wherein the intraluminal imaging devicecomprises an intracardiac echocardiography (ICE) catheter, and whereinthe imaging component comprises an ultrasound transducer array.